Abstract runtime creation of dirs into a function
Abstract runtime creation of dirs into a function

Currently the dir creation in ganeti-noded is in the main function. This
is not nice: we move it into a separate function and also add creation
of the OS_LOG_DIR (with different permissions, but in the same way).
This will permit cleanup of the creation of the OS_LOG_DIR from the
backend module (it's done multiple places currently).

Reviewed-by: imsnah

mbakke/ganeti,bitemyapp/ganeti,apyrgio/snf-ganeti,dimara/ganeti,bitemyapp/ganeti,dimara/ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,mbakke/ganeti,grnet/snf-ganeti,onponomarev/ganeti,andir/ganeti,yiannist/ganeti,leshchevds/ganeti,ganeti/ganeti,andir/ganeti,andir/ganeti,yiannist/ganeti,onponomarev/ganeti,leshchevds/ganeti,leshchevds/ganeti,apyrgio/ganeti,ganeti/ganeti,apyrgio/ganeti,ganeti/ganeti,ganeti-github-testing/ganeti-test-1,grnet/snf-ganeti